1. Field of the Invention
The present invention relates to a game machine and a method of controlling the game machine, and more particularly, a game machine, such as a slot machine, having a plurality of various kinds of symbols partially displayed and scrolled within a window and being designed to allow a player to stop the scroll of the symbols to decide the combination of symbols displayed within the window.
2. Description of the Related Art
There has been kept wide popularity of a game machine, such as a slot machine, comprising: a plurality of rotatable cylindrical reels each provided with various kinds of symbols on its outer surface at even intervals and independently rotatable about an axis; and a front panel having a window, through which some symbols of the reels are displayed, and a plurality of prize-winning lines on which the symbols of respective reels are positioned when the reels stop rotating. The game machine further comprises: a start lever for allowing the player to instruct the reels to start rotating and generating a start instruction; and a plurality of stop buttons for allowing the player to instruct the reels, respectively, to stop rotating and generating stop instructions respectively corresponding to the reels.
The reels stop rotating in response to the stop instructions, respectively, thereby resulting in the fact that the symbols of the reels are arranged on the prize-winning lines. The game machine is generally operated to evaluate the combinations of these symbols of the reels arranged on the prize-winning lines, and to then pay out a predetermined number of tokens as a prize if the combination of the symbols is coincident with any one of a plurality of predetermined winning combinations of the symbols.
Recently, the game machine of this type particularly called "pachi-slot" can be controlled by a microcomputer to display and scroll the symbols and to produce various visual and audio outputs, thereby making the game machine more attractive to the player.
More specifically, the game machine comprises controlling means, as representatively embodied by the microcomputer, for operating the reels in response to the player's instruction. The controlling means is operated to allow the rotating reels to stop rotating in response to the stop instructions, respectively, after a predetermined time, e.g., 190 msec determined by the existing Japanese law, has been passed since the stop instructions are respectively generated. The controlling means is further operated to previously decide a plan of the result of the game, to estimate the stop position of the last one of the reels to judge whether the combination of the symbols arranged on the winning line makes the result of the game coincident with the previously decided plan or not. The controlling means is, if necessary, operated to shift the position of the reel within the predetermined time to change the combination of the symbols in order to make the game result accord to the decided plan.
In the above conventional game machine, the reels can rotate in an only one-way direction. When the player pushes the stop button to issue the stop instruction, the corresponding reel cannot stop rotating in a moment, but decelerates and keeps it rotating to make the symbols shifted in the one-way direction by a predetermined number of symbols until the reel completely stops rotating. The number of shifting symbols is restricted within a predetermined number, e.g., 5 pieces of symbols. Commonly the player learns the arrangement of symbols on each reel by heart. After stopping the reels excepting the last one of the reels, the player watches the rotating symbols carefully and waits for a chance of winning a desired prize, as taking into account the degree of the deceleration of the reel and the number of shifting symbols.
This means that it is necessary for the player to master a high technique for watching the timing of stopping the rotation of the reel and pushing the stop button at this timing in order to obtain a desired combination of symbols thereby winning a desired prize. This makes the game machine more attractive to the player.
However, in the conventional game machine as described above, once the player missed bringing the desired symbol to a standstill on the winning line, the player loses the chance of winning the prize if the rotation of the reel has been decelerated to a low speed inadequate to make the symbol come full circle, because the one-way rotation of the reels makes it impossible to correct the standstill symbol after the desired symbol passed over the prize-winning lines. The player can thus judge that there is no chance of winning the prize, and then fails to keep up interest in the game until all of reels are stopped to bring the symbols to a standstill on the prize-winning line.